mainlining shenanigans
4fe581d7f1
This is a follow-up to Deepa's work on the timekeeping system calls, providing a y2038-safe syscall API for SYSVIPC. It uses a combination of two strategies: For sys_msgctl, sys_semctl and sys_shmctl, I do not introduce a completely new set of replacement system calls, but instead extend the existing ones to return data in the reserved fields of the normal data structure. This should be completely transparent to any existing user space, and only after the 32-bit time_t wraps, it will make a difference in the returned data. libc implementations will consequently have to provide their own data structures when they move to 64-bit time_t, and convert the structures in user space from the ones returned by the kernel. In contrast, mq_timedsend, mq_timedreceive and and semtimedop all do need to change because having a libc redefine the timespec type breaks the ABI, so with this series there will be two separate entry points for 32-bit architectures. There are three cases here: - little-endian architectures (except powerpc and mips) can use the normal layout and just cast the data structure to the user space type that contains 64-bit numbers. - parisc and sparc can do the same thing with big-endian user space - little-endian powerpc and most big-endian architectures have to flip the upper and lower 32-bit halves of the time_t value in memory, but can otherwise keep using the normal layout - mips and big-endian xtensa need to be more careful because they are not consistent in their definitions, and they have to provide custom libc implementations for the system calls to use 64-bit time_t. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAABAgAGBQJa4HbTAAoJEGCrR//JCVIniiUP/0mXR18lDCROYoVHgGwDHUas 9CjdGk+GvFFzRYvcoOgBjf8RhiUcYITyn2t9Kv52fZRv6RRaxD+qHWMXs8rnpmnm 59v/GWi4qdbrliCgxrUU6LMsRom4mjTXuZLqCoOrs7F2pGurQ3bq75m4IM7wsx/+ cucSSxLb+qmCeT5HF/7LbvVLm2X10RGW6iI+UeU267sitymUaGmuJGcF6WxioXB2 0u6mwlj62nlc07vSBJQQgSOuw+U095q6hS62uaNr7ZMByckbiPbVV9M4H5OFflqI Y70UohSue2LIYvJOhu70wQWs832W7sYb+Ia3fnMaX1AEIErtmGoBiIJ1lio1vYpb jVCPPsR0jWMg2MxGEGAEmEXQ7MZLme6yRmd08IFNJmRzuuzzuwXyz5hwz53ZJtIX dw0BZnw49b1Hy2oW03w6tbrnW7MlEkMMHM0wOSYGd0K8zJQUOSlW6p1m/UTTpsJQ G5CSaFWPtEfNPiS+E+w+C8TUtTs6SEZXn8/pIrXSnUjEu9QJvsCmxOroEW7D8pdD d4+13U5VzIXNlzf+/K1YZ2PIMmorDXkr2otMyi44naksWqc/p4NaikoINgq8QVm2 aoZ0ddlIbyTmiXvWfL7AVjmi7w2ACML8OoapITdWCr1Bfs+DUFNdOrFbdFA7psq7 L98FqbtoHwFLM7b3veF5 =7FX4 -----END PGP SIGNATURE----- Merge tag 'y2038-ipc' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground into timers/2038 Pull 'y2038: IPC system call conversion' from Arnd Bergmann: "This is a follow-up to Deepa's work on the timekeeping system calls, providing a y2038-safe syscall API for SYSVIPC. It uses a combination of two strategies: For sys_msgctl, sys_semctl and sys_shmctl, I do not introduce a completely new set of replacement system calls, but instead extend the existing ones to return data in the reserved fields of the normal data structure. This should be completely transparent to any existing user space, and only after the 32-bit time_t wraps, it will make a difference in the returned data. libc implementations will consequently have to provide their own data structures when they move to 64-bit time_t, and convert the structures in user space from the ones returned by the kernel. In contrast, mq_timedsend, mq_timedreceive and and semtimedop all do need to change because having a libc redefine the timespec type breaks the ABI, so with this series there will be two separate entry points for 32-bit architectures. There are three cases here: - little-endian architectures (except powerpc and mips) can use the normal layout and just cast the data structure to the user space type that contains 64-bit numbers. - parisc and sparc can do the same thing with big-endian user space - little-endian powerpc and most big-endian architectures have to flip the upper and lower 32-bit halves of the time_t value in memory, but can otherwise keep using the normal layout - mips and big-endian xtensa need to be more careful because they are not consistent in their definitions, and they have to provide custom libc implementations for the system calls to use 64-bit time_t." |
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| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
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| COPYING | ||
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| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.